The European Union is split over how to introduce a law requiring phone and Internet usage records to be stored to help fight terrorism in the wake of the London bombings, an EU official said on Monday.

The executive European Commission is drafting a proposal to harmonize the rules for storing telephone, mobile and e-mail records across the 25-nation bloc, but EU president Britain is promoting a separate initiative on the same issue.

The Commission's proposal could take up to three years because it would require the assent of the European Parliament, which is particularly sensitive to civil rights concerns and more open to lobbying by telecommunications companies.

A quick deal among member governments would be open to less public scrutiny and compliance would only be policed nationally.

The Commission says it is seeking to balance the imperatives of security and crime-fighting against privacy concerns over handing data to the police and the cost to telecoms companies of storing customer records.

Britain, supported by Ireland, France and Sweden, has led calls for EU governments to agree new rules among themselves, excluding the Parliament and the Commission, as London fears the two EU institutions could slow down decision-making.

"In the Commission's opinion they are not complementary initiatives," European Commission justice spokesman Friso Roscam-Abbing told a daily briefing, adding that the EU executive would launch its proposal in a few months.

"We have to make a choice. The European Union has to choose the instrument it goes for."

The four EU states proposed after the March 2004 Madrid bombings which killed 191 people that telecommunications data should be stored compulsorily for a minimum of one year.

The Commission has recommended a period of six months to a year to reduce the storage cost for companies.

EU interior ministers will discuss data retention at a special meeting on Wednesday called to speed up anti-terrorism cooperation after last Thursday's four bomb attacks on London's transport system, which killed at least 49 people.

Neither proposal calls for the content of electronic communications to be recorded but investigators want to be able to trace numbers dialed, including unsuccessful calls, and Internet addresses accessed.